This means it can run on 125 or 250V.
Dryers do NOT put out voltages and reread the label. No dryer of any kind that draws 30 amps, will be plugged into a power outlet.
What is the voltage of the power outlet that you intend to plug the dryer into?

The 250V is from across the end winding of the the secondary of a center tapped transformer located outside on a pole or in an underground housing and is used for the dryer's heating element. The 125 V is from one end of the center tapped transformer to the center tap and is used for the 125 V requirements of the dryer. The dryer you are looking at will work on the receptical if it's male plug fits the female receptical.

240 volts is the wall connector supply voltage , capable of 30 amps. The circuit breaker at the panel is is wired such to supply that rating. Your dryer value is typical. Make sure the plug on the cord matches the wall recept.